Hydrocarbon synthesized carbon nanotubes are grown on catalyst surfaces by reactive dehydrogenation of a high-temperature-stable hydrocarbon intermediate known as precursor soot. Dehydrogenation must occur at the interface between the metal with the nanotube and the precursor soot material in order for the nanotube to grow. The precursor soot can only lose hydrogen at the interface with the surrounding medium. Consequently, as the precursor soot film grows thicker hydrogen must diffuse further though the precursor soot medium in order to escape into the gas phase. It is this thickening of the precursor soot layer that causes the deactivation of the catalyst. A possible solution to this problem is to reduce the fuel input as the reaction rate builds. However, reducing the fuel input renders the process difficult to use in manufacturing operations.